Trouble with Templeted Client Functions

[Macalay7777]

Hi all! I'm working on writing a Display() function for a templates class program. The Display() function is a templated client function, not a part of the class, and is supposed to take in an argument called a_set and display the contents of the set. However, I am having trouble doing this. I've tried writing the function a few ways, but I would always get the wrong output. Down below I will provide you with the Display function I have written inside the Set.cpp file (not the main.cpp), and after the class implementation.

template <class ItemType> // this function displays the set
void DisplaySet(const Set<ItemType> &a_set) {

    int size = a_set.GetCurrentSize(); //gets size of the set
    cout << size << endl; //just to check
    int array[size]; //not sure if this is what I'm supposed to do
    for (int i = 0; i < size; i++) {
        cout << array[i] << endl; //I'm assuming I would need a for loop
    }                            //because I am working with array based     implementations
}

This is what I would have in my set (in the main.cpp file)

    
#include <iostream>
#include "Set.h"

int main() {

    int array_SetB[] = {1, 10, 3, 10, 5, 10};
    
    b_set.Add(array_SetB[0]);
    b_set.Add(array_SetB[1]);
    b_set.Add(array_SetB[2]);
    b_set.Add(array_SetB[3]);
    b_set.Add(array_SetB[4]);
    b_set.Add(array_SetB[5]);

    DisplaySet(b_set);
}

So the DisplaySet() function should display 1, 10, 3, 5. (My Add() function gets rid of duplicate numbers). However, I tend to get output along the lines of hexadecimal numbers or

1606415488
32767
7880

.

If any of you need to look at any of my implementation files for further reference, let me know. Many thanks!

[Yanson]

    int array[size]; //not sure if this is what I'm supposed to do
    for (int i = 0; i < size; i++) {
        cout << array[i] << endl; //I'm assuming I would need a for loop
    } 

The output here is undefined. You create an array witch by default is filled with garbage values. Then you output those values.

[Macalay7777]

Thank you for your reply, Yanson. So basically what I am doing now is just outputting the garbage values from the array in the function rather than from the array in the actual set? How then would I go about outputting the values I actually want to output? Would I have to include an int array as one of the parameters for the DisplaySet() function? Or is there a way I can display the contents of a_set (referring to the function parameter in DisplaySet()) without using an array? So something like:

template <class ItemType> // this function displays the set
void DisplaySet(const Set<ItemType> &a_set) {

cout << a_set << endl; //something along the lines of this? Without arrays
}

[Macalay7777]

Or if I wanted an array­-based implementation of the Set abstract data type, would I have to change

vector<ItemType> ToVector() const;

to a function like

int<ItemType> ToArray() const;

and then change the contents of ToVector() in the Set.cpp to a ToArray() function?